This is the 1st most frequent Spanish word.
de
"De" means "of," "from," or indicates possession or origin.
Here, 'de' illustrates content, linking the glass and the water it contains.
Necesitamos un vaso de agua.
We need a glass of water.
In this case, 'de' is used to express origin, indicating that Maria is 'from' Colombia.
María viene de Colombia.
Maria comes from Colombia.
The word 'de' in this sentence is used to indicate a specific type or category, linking 'book' with 'math.' It shows possession or association.